I have a very annoying problem. My HTC M8 is not recognized by my new Windows 8.1 Professional System.
If I connect the phone to my PC Windows plays the "new device" sound but nothing more happens. Neither in normal MTP-Mode nor in the USB debugging mode. I checked out the Windows device manager but the phone is not listed.
First I thought that it might be a problem with the Android Revolution HD 7.0 ROM, but the phone works on my notebook (Windows 7) without installing any special drivers. And my old Samsung Galaxy Nexus works with Windows 8.1.
I installed the HTC Sync Manager... didn't help.
I installed the HTC Driver package... didn't help.
I installed the Universal ADB Driver... didn't help either.
Then I tried different USB ports.. nothing